There are two types of Achromatopsia. These are the complete achromatopsia and incomplete achromatopsia. Achromatopsia is an inherited condition that affects approximately 1 in every 33,000 Americans. It is also known as rod monochromatism. This condition is related with color blindness, visual acuity loss, extreme light sensitivity and nystagmus. It is a condition found all over the world with varying incidence. Complete Achromatopsia means without color and is defined as little or no function of the cone cells. Persons with achromatopsia are only able to perceive black, white and shades of gray. Patients with complete achromatopsia have no real understanding of the concept of color. A color like red may be perceived as dark gray while yellow may be perceived as a light gray. The vision is much like that of a black and white photograph with varying shades of gray. On the other hand,incomplete achromatopsia have profound color impairment, but do have a small residual amount of color vision and slightly better visual acuity due to the presence of some functioning cone cells in the retina. Achromatopsia is a recessive inherited condition. It requires both parents to contribute a gene in order for the condition to occur. All the offspring of an achromat may carry one gene for achromatopsia. In order to pass the condition onto their children, it would require having children with someone else carrying the same gene. This would be extremely unlikely in today’s very mobile populations. However, in the Western Pacific, there is a small island of Pingelap that has a high incidence of achromatopsia. This population has been studied significantly because of this condition. Through genealogy, it was traced back to 1775 to one man who survived a typhoon which killed most of the islands residents. This man had a mutation of the CNGB3 gene which is essential in the eye’s photoreceptors and ultimately vision. He passed this gene on to his ancestors who have subsequently been affected by achromatopsia. The other group of highly studied achromats is Western European families. The genetic studies there have found another gene that is responsible for their vision problems. The CNGA3 gene was found to cause the condition in this population. Both of these genes affect the cone cells of the eye. Cone cells are responsible for our central, detail vision. Additionally, the three different types of cone cells are responsible for our color vision.

They are packed by the millions into the macula of the retina. The peripheral retina is made of rod cells. These cells are more sensitive to light, but cannot differentiate color. Achromatopsia early detection in children is present from birth. The first signs may be the presence of nystagmus, a pendular quivering of the eyes and light sensitivity with squinting in bright light. An electroretinogram may show an abnormal photopic or daylight signal while maintaining a normal scotopic or night vision signal. When the child is old enough, color vision testing like the Sloan Achromatopsia. A vital new treatment for those with achromatopsia is the use of red central soft contact lenses.These contact lenses has a small red circle that when properly positioned looks like the pupil of the eye. On the eye they appear as dark circles looking just like the normal pupil of the eye. These red contact lenses not only reduce the light entering each eye, but allow primarily red light to enter the eye. Red light allows the remaining rods to function better, and in complete achromatopsia, where the patient sees no color, the patient is not aware of the red hue. In the incomplete form of achromatopsia, patients report it enhances their ability to detect red stoplights and red brake lights. These lenses work much the way submariners in World War II turned red lights inside the submarine on to allow their eyes to adapt for night vision before surfacing at night. With the contact lenses in place, mild sunglasses may be worn outside and no filters are usually required inside. We find that patients are amazed by the dramatic improvement of their functioning in bright light.